The present invention relates to a vane compressor.
Japanese Unexamined Utility Model Application Publication No. 49-26104 discloses a vane compressor. The vane compressor includes a housing having therein a cylindrical rotor chamber, a rotor, and four vanes. The rotor is provided in the rotor chamber so as to be rotatable about the axis of rotation. The rotor has two first vane slots formed extending radially toward the axis of rotation and two second vane slots that are also formed extending radially toward the axis of rotation at positions opposite to the respective first vane slots with respect to the axis of rotation. The four vanes include two first vanes that are disposed in the first vane slots so as to be slidable in and out of the first vane slots and two second vanes that are disposed in the second vane slots so as to be slidable in and out of the second vanes.
The rotor has two communication holes that extend in radial directions. One of the communication holes is formed in communication at the opposite ends thereof with one of the first vane slots and one of the second vane slots that are opposite to each other with respect to the extending direction of the communication hole, and the other of the communication holes is in communication at the opposite ends thereof with the other first vane slot and the other second vane slot. A transmission pin is inserted in each of the communication holes.
A first coil spring is accommodated in each of the first vane slots, and a second coil spring is accommodated in each of the second vane slots. Specifically, each first coil spring is disposed between the vane and one end of the transmission pin so that the first vane and the transmission pin are urged by the first coil spring in opposite directions. Each second coil spring is disposed between the bottom surface of the second vane and one end of the transmission pin so that the second vane and the transmission pin are urged by the second coil spring in opposite directions away each other.
According to the vane compressor of the Publication, the movement of the first vane in the first vane slot is transmitted to its corresponding opposite second vane through the transmission pin and the first and second coils springs. Similarly, the movement of the second vane in the second vane slot is transmitted to its corresponding opposite first vane through the transmission pin and the first and second coil springs. The coil springs absorb or allow the variation in the distance between the first and second vanes sliding in and out of the first vane slot and the second vane slot, respectively, by extending and compressing.
According to the vane compressor of the Publication, with the compression and extension of the first and second coil spring, the first vanes and the second vanes slide in and out of the first vane slots and the second vane slots, respectively. Facing surfaces of two side plates disposed on opposite sides of the rotor chamber, the inner peripheral surface of the rotor chamber, the outer peripheral surface of the rotor, and two adjacent vanes form a compression chamber. With the rotation of the rotor, fluid is taken into the compression chamber and compressed.
However, according to the vane compressor of the Publication, in which the first vanes and the transmission pins are disposed separate from each other, there is a fear that the bottom surfaces of the first vanes may be brought into contact with the end of the transmission pins when the first vanes slide in the first vane slots, which causes development of intermittent noise with the rotation of the rotor. This also holds true for the second vanes and the transmission pins.
Further, according to the vane compressor of the Publication, the first coil spring urges the first vane by direct contact with the bottom surface of the first vane, and the second coil spring urges the second vane by direct contact with the bottom surface of the second vane. The first and second coil springs may not urge the first and second vanes stable, and the fluid may leak from the compression chamber. Accordingly, it is difficult for the vane compressor to improve its compression efficiency.
The present invention which has been made in view of the circumstances above is directed to providing a vane compressor that is silent in operation and offers an improved compression efficiency.